Aghhh have I just killed my CPU? System inactive with the CPU in the socket and the level down..

Caporegime
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Hi guys, having a bit of a new problem here so would appreciate a bit of help.

I was just replacing a GPU and I nudged (not banged) the heatsink attached to the CPU. I checked it was still seated ok then didn't think anything of it and put the system back together and pressed the power button. Nothing. Nada. The mobo power button lights up which is an ok sign, but it wouldn't post when pressing the power button. Reseated the GPU, checked cables. Again, wouldn't post. Nada,

The CPU and heatsink again seem fine and sturdily seated so I do some googling and see a lot of people having a similar problem and needing to reseat the CPU. So I take off the heatsink and there is a lot of thermal paste glooped at the sides so I must have put too much on originally. My bad. So I clean up the CPU and heatsink with alcohol lens wipes and some of it goes around the CPU, but I clean it off as best I can with and reseat the CPU. No post.

I then unseat the CPU and press the power button and the mobo whirrs into life. I repeat this successfully multiple times, so the problem is definitely the CPU. However, although the CPU looks clean and the pins look ok it just doesn't whirr into life with the CPU seated and the level is down. The moment I lift the level, it posts.

  • Is it likely that there is some paste somewhere on the CPU that is shorting the mobo?
  • Could I have got some traces ofthermal paste inside the socket itself and will this be a bigger problem?

Advice would be appreciated please. :)
 
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Can you post you specs? If it's an amd cpu, you'll need to check very carefully for bent pins from all angles. Also check the silly things like your power cables.

What thermal paste are you using? If it's non conductive then it won't short. Was it on the socket?
 
Associate
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Is it an Intel, or Amd?
Psu make and wattage, Gpu make and number of power connectors please.
 
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The problem might be the motherboard’s connection to the CPU, so the board starts with the CPU out. The processor itself could be fine.

But that’s difficult to test without another processor.
 
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Well if it's an amd, nudging the cooler could have compressed the cpu. Otherwise, check all the cable connections at the psu end, sometimes when installing hardware you got loosen a connection from the psu end
 
Caporegime
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Can you post you specs? If it's an amd cpu, you'll need to check very carefully for bent pins from all angles. Also check the silly things like your power cables.

What thermal paste are you using? If it's non conductive then it won't short. Was it on the socket?
Thanks guys I appreciate it. Specs are in my sig but I forgot to put them in my main post.

l MSI Unify X570 l AMD 3300x l 1660 Super l
l 32GB Gskill Neo Z PC3600 l Scythe Mugen 5 l
l Adata SX8200 Pro 2TB SSD l BeQuiet! 500DX l
l Seasonic Focus GX850 l

  • Thermal paste is Noctua NH1 which is NOT conductive (yay) https://noctua.at/en/nt-h1-3-5g
  • Doesn't seem to be paste in the socket.
  • PSU connections seem fine.
  • Board connections seem fine.
  • Tried resetting CMOS.
  • Pins may be fractionally bent but it's really hard to tell, I need a magnifying glass.
  • The fact everything boots up without the CPU lever down brings me hope that it's really just a dead CPU. Mobo would be a disaster.
  • I may be forced to buy a 5800+ instead of waiting another 1-2 months for a 5900x. Not sure I will ever forgive AMD for this stock debaucle.
Well if it's an amd, nudging the cooler could have compressed the cpu. Otherwise, check all the cable connections at the psu end, sometimes when installing hardware you got loosen a connection from the psu end

Do you mean compressed as in pending the pins, or...?
 
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Caporegime
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Interestingly, when I put the CPU in the socket (but DON'T put down the lever, it just sits loose in the socket) and the power is all connected then the PC spins into life without my pressing the power button...
 
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Do you mean compressed as in pending the pins, or...?
Yes, I know when I've had air coolers waaaaay in the past and I was fitting stuff into the case I would sometimes press against the heatsink.
Do you know anyone who could try your cpu in another mobo?
And one last thing, can you power up the system and get to bios without the cpu and the lever down?
 
Caporegime
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Yes, I know when I've had air coolers waaaaay in the past and I was fitting stuff into the case I would sometimes press against the heatsink.
Do you know anyone who could try your cpu in another mobo?
And one last thing, can you power up the system and get to bios without the cpu and the lever down?
Hmm no there was no signal to the monitor without the CPU inside either. Should it get to the BIOS? I've never tried it without a CPU before.

EDIT - Doesn't make sense that it would work though...
 
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Associate
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Just trying to eliminate the possibility that it's the motherboard. I was rushing and responding to your thread. You should have Q-Led just by your 24pin motherboard socket. do you get a red light on the bottom most led which is the cpu warning light?
Or an error code on your Post display at the bottom right of your board.
 
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I wonder if the motherboard has cracked with the tap you gave it. When I say motherboard it could be a track, or solder joint or even a hole through plating.
I had that once and the moment I placed any pressure on anything, it just didn't work any more. Often heatsinks are a bit tight and can put the board under pressure. A tap can really overload an already stressed board.

Incidentally, some lens wipes contain fragrance which may cause harm. I would try getting a little bottle of isopropanol for future cleaning. It may be worth the cost of a bottle to rinse the CPU in just in case there are any deposits on it, but I think this is unlikely to work.
 
Caporegime
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Just trying to eliminate the possibility that it's the motherboard. I was rushing and responding to your thread. You should have Q-Led just by your 24pin motherboard socket. do you get a red light on the bottom most led which is the cpu warning light?
Or an error code on your Post display at the bottom right of your board.
I only get the LED warning when when I take out the power cable.

did you try refitting old GPU ?

Yes, same problem.
I wonder if the motherboard has cracked with the tap you gave it. When I say motherboard it could be a track, or solder joint or even a hole through plating.
I had that once and the moment I placed any pressure on anything, it just didn't work any more. Often heatsinks are a bit tight and can put the board under pressure. A tap can really overload an already stressed board.

Incidentally, some lens wipes contain fragrance which may cause harm. I would try getting a little bottle of isopropanol for future cleaning. It may be worth the cost of a bottle to rinse the CPU in just in case there are any deposits on it, but I think this is unlikely to work.
I didn't hear or see any signs of this and would be surprised.

I have just ordered another CPU to try so i that works then we know the old CPU was the problem... if not then it could be the mobo. Lets pray it's the CPU.
 
Caporegime
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Ok I just rechecked the CPU and one of the pins looked funny, so I tried to manipulate it a bit straighter and made it even worse. I tried to put it back in the socket and the mobo immediately started to turn on which seems to me, with my kindergarten level of electrical engineering, like the CPU is causing something to short. For now I am going to write this CPU off as destroyed until the new one arrives tomorrow. Very disheartening though, especially as it was my fault somehow in the first place.
 
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Ok I just rechecked the CPU and one of the pins looked funny, so I tried to manipulate it a bit straighter and made it even worse. I tried to put it back in the socket and the mobo immediately started to turn on which seems to me, with my kindergarten level of electrical engineering, like the CPU is causing something to short. For now I am going to write this CPU off as destroyed until the new one arrives tomorrow. Very disheartening though, especially as it was my fault somehow in the first place.
Good luck, you could also try RMA on CPU , nothing to loose
 
Soldato
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Ok I just rechecked the CPU and one of the pins looked funny, so I tried to manipulate it a bit straighter and made it even worse. I tried to put it back in the socket and the mobo immediately started to turn on which seems to me, with my kindergarten level of electrical engineering, like the CPU is causing something to short. For now I am going to write this CPU off as destroyed until the new one arrives tomorrow. Very disheartening though, especially as it was my fault somehow in the first place.

you shoudnt even have any power going to the motherboard if your removing components especially the CPU, PSU should be off.
 
Caporegime
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you shoudnt even have any power going to the motherboard if your removing components especially the CPU, PSU should be off.
Yes you are right I know its not ideal, but I was tearing my hair out troubleshooting. Tomorrow will be the day of judgement when I have a new CPU to try.... I will be very unhappy if the mobo is a problem but the fact it all lights up and does its thing gives me hope.
 
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Yes you are right I know its not ideal, but I was tearing my hair out troubleshooting. Tomorrow will be the day of judgement when I have a new CPU to try.... I will be very unhappy if the mobo is a problem but the fact it all lights up and does its thing gives me hope.

The spontaneous power on definitely shouldn't happen. Hate to make things worse but I'd seriously look at the mobo as the culprit.
 
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